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In article <28v7ou$f8d@news.u.washington.edu> johnreed@stein1.u.washington.edu (John Reed) writes:

[...]

>My last question is simply: in 
>what types of organisms does parthanogenesis occur?  I know it occurs in 
>insects, what about other arthropods, plants (I believe it does), other 
>animals, fungi?  Thanks for any replies.

	It also occurs in several species of lizard.

johnreed@stein1.u.washington.edu (John Reed) writes:
>I am interest in knowing whether parthanogenesis has evolved in the male 
>sex of any species.  I would presume not, for evolutionary reasons, but I 
>would like to know for sure.  I would also like to know other peoples 
>opinions as to why this has not occured.  

Well, my own opinion as to why this has/would not occur is more for
physiological than "evolutionary" reasons:  males don't do parthenogenesis
because if they did, they'd be called females.  My understanding is that
"male" and "female" are defined in general by the relative motility of
their gametes (i.e. "sperm/pollen" are motile, "eggs/ova" are not), and
consequently, in those species which "give birth", by who bears the young
or lays the egg.

>My last question is simply: in 
>what types of organisms does parthanogenesis occur?  I know it occurs in 
>insects, what about other arthropods, plants (I believe it does), other 
>animals, fungi?  Thanks for any replies.

As far as plants go, I think the runners that plants such as strawberries
and (I think?) grasses put forth by way of asexual reproduction are
considered a form of parthenogenesis.  There is also a species of lizard
that parthenogeneses (would that be the verb form?).  Probably there are
more but I don't know of any.

>--------------------------------------------------------------------------
>John Reed


--jim

-- 
Jim Loats                   * "I pass the test.  I shall diminish,
loats1@husc.harvard.edu     *  and go into the West, and remain
Bacterial Motor Works--the  *  Galadriel."
Ultimate Swimming Machine!  *             -- J.R.R. Tolkien

In article <loats1.749942282@husc9>,
James Loats <loats1@husc9.harvard.edu> wrote:
>>I am interest in knowing whether parthanogenesis has evolved in the male 
>>sex of any species.  I would presume not, for evolutionary reasons, but I 
>>would like to know for sure.  I would also like to know other peoples 
>>opinions as to why this has not occured.  
>
>Well, my own opinion as to why this has/would not occur is more for
>physiological than "evolutionary" reasons:  males don't do parthenogenesis
>because if they did, they'd be called females.  My understanding is that
>"male" and "female" are defined in general by the relative motility of
>their gametes (i.e. "sperm/pollen" are motile, "eggs/ova" are not), and
>consequently, in those species which "give birth", by who bears the young
>or lays the egg.

Why couldn't a motile gamete parthenogeneses (as you say, verb form?).  
The reason I presumed it never occured was that motile gametes don't have 
the surrounding tissues (placenta, endosperm) for the developing emryo, 
whether it is derived from parthogenesis or fertilization.  I still don't 
see any real reason you COULDN'T have parthenogenesis in males, just a 
good explanation for why it is at least less common.  So far I haven't 
got any replies indicating that it does occur in ANY male of ANY species 
on Earth.

>-- 
>Jim Loats                   * "I pass the test.  I shall diminish,
>loats1@husc.harvard.edu     *  and go into the West, and remain
>Bacterial Motor Works--the  *  Galadriel."
>Ultimate Swimming Machine!  *             -- J.R.R. Tolkien

--------------------------------------------------------------------------
John Reed
College of Forest Resources, AR-10
University of Washington
Seattle, WA 98195
Internet: johnreed@u.washington.edu
--------------------------------------------------------------------------

In article <28v7ou$f8d@news.u.washington.edu>, johnreed@stein1.u.washington.edu (John Reed) writes:
> I am interest in knowing whether parthanogenesis has evolved in the male 
> sex of any species.  I would presume not, for evolutionary reasons, but I 
> would like to know for sure.  I would also like to know other peoples 
> opinions as to why this has not occured.  My last question is simply: in 
> what types of organisms does parthanogenesis occur?  I know it occurs in 
> insects, what about other arthropods, plants (I believe it does), other 
> animals, fungi?  Thanks for any replies.
> 

I know that parthenogenesis occurs in some lizards - There was an article on an
American desert species a year or two ago in Sci Am.
On males - they tend not to have the reproductive apparatus, perhaps? If males
had functioning female I suspect we would call them female. I do not think this
issue could be resolved chromosomally in all species. I understand that
crocodilian sex is determined by incubation temperature?
___________________________________________________________________________
ROBERT BOOT                                             R.BOOT@cc.uq.edu.au
HERSTON MEDICAL LIBRARY
The University of Queensland                       Telephone +61 7 365 5354
Brisbane Qld 4072  AUSTRALIA                       Facsimile +61 7 365 5243

[...]
: Well, my own opinion as to why this has/would not occur is more for
: physiological than "evolutionary" reasons:  males don't do parthenogenesis
: because if they did, they'd be called females.  My understanding is that
: "male" and "female" are defined in general by the relative motility of
: their gametes (i.e. "sperm/pollen" are motile, "eggs/ova" are not), and
: consequently, in those species which "give birth", by who bears the young
: or lays the egg.

Not necessarily. In the Hippocampi (sea horses), males give birth to the
offspring. 

: >My last question is simply: in 
: >what types of organisms does parthanogenesis occur?  I know it occurs in 
: >insects, what about other arthropods, plants (I believe it does), other 
: >animals, fungi?  Thanks for any replies.

Although it doesn't occur naturally in higher vertebrates, it has been
possible to artificially induce it in turkeys as well as in mice, but
in the latter the parthenogenetic offspring dies before it's born
(presumably due to genomic imprinting - ie certain genes must be received
from the father for proper development to occur)

: As far as plants go, I think the runners that plants such as strawberries
: and (I think?) grasses put forth by way of asexual reproduction are
: considered a form of parthenogenesis.  There is also a species of lizard
: that parthenogeneses (would that be the verb form?).  Probably there are
: more but I don't know of any.

I guess the verb form would be to parthenogenerate. The thing with
strawberries et al is that the clones are generated from vegetative (ie
diploid) tissue, whereas in most true parthenogenonts the offspring is
haploid (having arisen from the gametes). If I remember well, however,
there are at least two different parthenogenetic strategies, one of which
bypasses meiosis altogether, thus giving rise to diploid offspring. 


Julian Blanc

johnreed@stein1.u.washington.edu (John Reed) writes:

>I am interest in knowing whether parthanogenesis has evolved in the male 
>sex of any species.  I would presume not, for evolutionary reasons, but I 
>would like to know for sure.  I would also like to know other peoples 
>opinions as to why this has not occured.  [question deleted]

Well, I'd say one of the reasons why males of any species are not capable of
parthenogenesis (as far as I know) is because of the different forms of
gametogenesis that occur in male and female.  The gametes produced by
males tend to be little sacs of DNA with not much in the way of cell
cytoplasm, whilst females tend to produce what could be considered a whole
cell that is lacking half its chromosome complement - probably an easier start
point for parthenogenesis to occur.  Anyway, aren't the products of
parthenogenesis clones of the parent?


Just my two cents worth.  Any other opinions?


-- 
Lynne Shandley                          bunny@zikzak.apana.org.au

"...and his faithful sidekick, Stupid the Kid."
                                        - the Ren and Stimpy Show

In article <loats1.749942282@husc9> loats1@husc9.harvard.edu (James Loats) writes:
>johnreed@stein1.u.washington.edu (John Reed) writes:
>>I am interest in knowing whether parthanogenesis has evolved in the male 
>>sex of any species.  I would presume not, for evolutionary reasons, but I 
>>would like to know for sure.  I would also like to know other peoples 
>>opinions as to why this has not occured.  
>
>Well, my own opinion as to why this has/would not occur is more for
>physiological than "evolutionary" reasons:  males don't do parthenogenesis
>because if they did, they'd be called females.  My understanding is that
>"male" and "female" are defined in general by the relative motility of
>their gametes (i.e. "sperm/pollen" are motile, "eggs/ova" are not), and
>consequently, in those species which "give birth", by who bears the young
>or lays the egg.
>
>>My last question is simply: in 
>>what types of organisms does parthanogenesis occur?  I know it occurs in 
>>insects, what about other arthropods, plants (I believe it does), other 
>>animals, fungi?  Thanks for any replies.
>
>As far as plants go, I think the runners that plants such as strawberries
>and (I think?) grasses put forth by way of asexual reproduction are
>considered a form of parthenogenesis.  There is also a species of lizard
>that parthenogeneses (would that be the verb form?).  Probably there are
>more but I don't know of any.
>
>>--------------------------------------------------------------------------
>>John Reed
>
>
>--jim
>
>-- 
>Jim Loats                   * "I pass the test.  I shall diminish,
>loats1@husc.harvard.edu     *  and go into the West, and remain
>Bacterial Motor Works--the  *  Galadriel."
>Ultimate Swimming Machine!  *             -- J.R.R. Tolkien

In article <293nbg$3il@zikzak.apana.org.au>
Lynne Shandley, bunny@zikzak.apana.org.au writes:
>Well, I'd say one of the reasons why males of any species are not capable of
>parthenogenesis (as far as I know) is because of the different forms of
>gametogenesis that occur in male and female.  The gametes produced by
>males tend to be little sacs of DNA with not much in the way of cell
>cytoplasm, whilst females tend to produce what could be considered a whole
>cell that is lacking half its chromosome complement - probably an easier start
>point for parthenogenesis to occur.  Anyway, aren't the products of
>parthenogenesis clones of the parent?

That is one kind of parthenogenesis, termed apomixis. That is when unreduced
eggs complete development without fertilization, sometimes involving 
pseudogamy. Examples include digenean trematodes, bdelloid rotifers, some
nematodes, tardigrades, coccids, cladocerans, aphids, cynipid wasps,
telid lizards, the clam Lasaea (all but the last example from Bell, G. 1982:
The Masterpiece of Nature..., p. 36). 

Another kind of parthenogenesis is automictic thelytoky, in which syngamy
occurs between nuclei of the same (female) gender, sometimes involving
pseudogamy. An example is when a polar body fuses with the oocyte haploid
nucleus. This is very much like self-fertilization in its genetic consequences.
It is a form of severe inbreeding, which will lead to very low (if any)
heterozygosity, in contrast to apomixis which preserves heterozygosity.

I recommend Bell's book for a review of parthenogenesis, although you will
have to catch up on examples published in the last decade. I would assume
that you won't find examples of parthenogenetic "males," for reasons
others have mentioned.

Doug

John Reed writes
 My last question is simply: in
what types of organisms does parthanogenesis occur?  I know it occurs in
insects, what about other arthropods, plants (I believe it does), other
animals, fungi?
<

Lizards, for one. Lot's of all female (=parthenoform)
whiptail lizards *Cnemidophorus* sp. in Texas. 

ramki


L.Ramakrishnan
Zoology Dept. UT Austin

In article <29hhsp$6rc@happy.cc.utexas.edu> ramki@happy.cc.utexas.edu (Lakshmikantan Ramakrishnan) writes:

   John Reed writes
    My last question is simply: in
   what types of organisms does parthanogenesis occur?  I know it occurs in
   insects, what about other arthropods, plants (I believe it does), other
   animals, fungi?
   <

   Lizards, for one. Lot's of all female (=parthenoform)
   whiptail lizards *Cnemidophorus* sp. in Texas. 

fish (black molly, I think)

birds (there's a parthenogenic turkey farm in New Jersey)

mechanical disturbances of unfertilized amphibian eggs can induce cell
division but I don't remember if can develop fully.

   ramki


   L.Ramakrishnan
   Zoology Dept. UT Austin
--
 John Edstrom | edstrom @ elmer.hsc.ucalgary.ca
 Division of Neuroscience
 University Calgary Facutly of Medicine
 3330 Hospital Drive NW
 Calgary, Alberta       T2N 3Y4
 (403) 220 4493  voice
 (403) 283 2700  FAX

In article <EDSTROM.93Oct14091639@elmer.hsc.ucalgary.ca>,
John Edstrom <edstrom@elmer.hsc.ucalgary.ca> wrote:
>birds (there's a parthenogenic turkey farm in New Jersey)

HUH??  Are you sure this is right? 

One tricky thing with birds is that the females are heterogametic (XY) 
and the males are homogametic (XX), the opposite of mammals.  So if 
parthenogenesis really happens...if an X egg develops 
parthenogenetically, you end up with an XX male, who cannot create eggs, 
and you stop right there.  If a Y egg develops parthenogenetically, you 
end up with a YY embryo, which dies.

So are you sure about the turkeys, or could it be some other phenomenon 
you are thinking of?  Sex-change has very rarely been observed in birds 
-- it was either in chickens or turkeys -- but I don't think the gametes 
of a sex-changed individual could be completely normal.  Let's see, if 
you had a female who sex-changed to become a male, and she produced X and 
Y sperm, and she mated with a normal XY female, and her sperm were 
functional, you'd get 1/4 XX males, 1/2 XY females, 1/4 YY dead eggs.  
Hmm.  I suppose it's conceivable.  But I doubt her sperm would be normal 
in the first place.  Hmm.  Clearly I have to go read up on this.


Kathleen

In article <28v7ou$f8d@news.u.washington.edu> John Reed,
johnreed@stein1.u.washington.edu writes:
>I am interest in knowing whether parthanogenesis has evolved in the male 
>sex of any species.  I would presume not, for evolutionary reasons, but
I 
>would like to know for sure.  I would also like to know other peoples 

Stand by for a statement from the village idiot:

I think the reason parthenogenesis is noted only in females is
linguistic.  Parthenogenesis was by definition reserved for females when
I was a lad.  In males it was called androgenesis.  My memory is a bit
dim on this because the article I am recalling was read about 35 years
ago.  I cannot recall if "androgenesis" was just a linguistic alternative
to parthenogenesis.

Parthenogenesis is derived from the Greek for "virgin birth."  I never
took classical Greek and do not have access to a Greek grammer text, but
my guess is that parthenos is feminine.  The Parthenon was the temple
devoted to the virgin-goddess Athena.

A quick check with a very large Webster's in a lab downstairs has
confirmed my idea about parthenos being a word that applied to maidens. 
However, androgenesis is defined as "male parthenogenesis" and is
contrasted with gynogenesis as the female form of parthenogenesis.  You
learn something everyday!

Jim Owens
_______________________________________________________
The Secretary will deny any connection to me if I am caught.

In article <EDSTROM.93Oct14091639@elmer.hsc.ucalgary.ca> edstrom@elmer.hsc.ucalgary.ca (John Edstrom) writes:
>In article <29hhsp$6rc@happy.cc.utexas.edu> ramki@happy.cc.utexas.edu (Lakshmikantan Ramakrishnan) writes:
>
>   John Reed writes
>    My last question is simply: in
>   what types of organisms does parthanogenesis occur?  I know it occurs in
>   insects, what about other arthropods, plants (I believe it does), other
>   animals, fungi?
>   <
>
>   Lizards, for one. Lot's of all female (=parthenoform)
>   whiptail lizards *Cnemidophorus* sp. in Texas. 
>
>fish (black molly, I think)
>
>birds (there's a parthenogenic turkey farm in New Jersey)
>
>mechanical disturbances of unfertilized amphibian eggs can induce cell
>division but I don't remember if can develop fully.
>
>   ramki
>
>
>   L.Ramakrishnan
>   Zoology Dept. UT Austin
>--
> John Edstrom | edstrom @ elmer.hsc.ucalgary.ca
> Division of Neuroscience
> University Calgary Facutly of Medicine
> 3330 Hospital Drive NW
> Calgary, Alberta       T2N 3Y4
> (403) 220 4493  voice
> (403) 283 2700  FAX
>
>